Shelly Control

[mojonba]

Hi Everybody,

Before I knew about Nixie, I turned on/off my pool heater via a Wifi Shelly Relay using Google Home. I am now setting up Nixie and was wondering that I could "avoid" rewiring the heater control with a Relay Hat if Nixie could control Shelly. Shelly has extensive control via Http/ MqTT etc. For example these/ commands operate the relay via Http. Can you guys point me in the right direction as far as doing this?

[tagyoureit]

You can do custom http/mqtt bindings.

[mojonba]

I spent some time on the weekend to see if I could tackle this myself using the valveRelays.js custom binding as an example. Unfortunately I hit many roadblocks as the variables used by heaters are not the same as the one used valves. Can you point me in the right direction? Shelly's MQTT implementation appears to be currently broken (unable to authenticate). So Http commands would be the way to go. I have tried them and they work perfectly.

[tagyoureit]

Yup!

Shelly Heater Control Binding

Automatically controls a Shelly relay based on your pool heater status. When the pool controller turns the heater ON, the Shelly relay turns ON. When the heater turns OFF, the relay turns OFF.

Quick Setup

1. Create the Binding File

1. Create a new file named shellyHeaterControl.json
2. Copy and paste the following code into it:

{
  "context": {
    "name": "shellyHeaterControl",
    "options": {
      "method": "GET",
      "path": "@bind=vars.useShellyGen2 ? `/rpc/Switch.Set?id=${vars.shellyRelayChannel}&on=${data.heatStatus.val > 0}` : `/relay/${vars.shellyRelayChannel}?turn=${data.heatStatus.val > 0 ? 'on' : 'off'}`;",
      "headers": {}
    },
    "vars": {
      "poolBodyId": 1,
      "shellyRelayChannel": 0,
      "useShellyGen2": false
    }
  },
  "events": [
    {
      "name": "body",
      "filter": "@bind=data.id; === @bind=vars.poolBodyId;",
      "description": "Mirror pool heater status to Shelly relay (supports Gen1 and Gen2)"
    }
  ]
}

3. Save the file

2. Customize Settings (Optional)

Before uploading, you can customize these settings in the JSON file:

Relay Channel (line 11: "shellyRelayChannel"):

• Single relay devices (1, 1PM, Plus 1, Plug): use 0
• Multi-relay devices (2.5, Pro 2, Pro 3, Pro 4PM): change to 1, 2, or 3 if needed

Device Generation (line 12: "useShellyGen2"):

• Gen1 / Plus devices (1, 1PM, 2.5, Plus 1, Plus 1PM, Plus Plug): false (default)
• Gen2 / Pro devices (Pro 1, Pro 2, Pro 3, Pro 4PM): change to true

Body ID (line 10: "poolBodyId"):

• Pool: 1 (default)
• Spa: change to 2

3. Upload the Binding File

Go to Setup → Controller → Interfaces in the web UI:

1. Click "+ Add Interface"
2. Click "Upload Bindings" button
3. Select your shellyHeaterControl.json file
4. The file will be uploaded to the server

4. Add the Interface

1. Name: "Shelly" (or any name you like)
2. Type: Select "Http"
3. Binding: Select "shellyHeaterControl" from the dropdown
4. Click "Add Interface"

5. Configure Connection

Click on the newly added interface to configure:

• Host: Your Shelly device IP address (e.g., 192.168.1.50)
• Port: 80 (default)
• Protocol: http:// (default)

Click Save.

How It Works

The pool controller monitors temperature vs setpoint and manages heater logic. This binding simply mirrors the heater state:

• Heater ON → Shelly relay ON
• Heater OFF → Shelly relay OFF

Shelly Commands Used

Gen1 / Plus Devices (default):

• ON: http://192.168.1.50/relay/0?turn=on
• OFF: http://192.168.1.50/relay/0?turn=off

Gen2 / Pro Devices:

• ON: http://192.168.1.50/rpc/Switch.Set?id=0&on=true
• OFF: http://192.168.1.50/rpc/Switch.Set?id=0&on=false

Troubleshooting

Relay not responding:

1. Verify the Shelly IP address is correct in the interface settings
2. Test the Shelly: curl "http://192.168.1.50/relay/0?turn=on"
3. Check relay channel number matches your device
4. Verify Gen1 vs Gen2 setting matches your device

Check logs:

• Web UI: System → Logs
• Look for: Sending [body] request to Shelley
• Errors will show connection issues

Compatible Devices

Use useShellyGen2: false (default):

• Shelly 1, 1PM, 1L, 2.5
• Shelly Plus 1, Plus 1PM, Plus 2PM, Plus Plug
• Shelly Plug, Plug S, Uni, 3EM

Use useShellyGen2: true:

• Shelly Pro 1, Pro 1PM
• Shelly Pro 2, Pro 2PM
• Shelly Pro 3, Pro 4PM

Note: Shelly Plus devices work with both Gen1 and Gen2 commands. Use false (Gen1) unless you specifically need Gen2 features.

References

• Shelly HTTP Commands Guide
• Shelly Gen2 RPC API Documentation
• nodejs-poolController Bindings Wiki

[mojonba]

Awesome. Thanks Much!. Just added the Shelly Interface. I am guessing I need to add a Heater with an Http Connection. Am I supposed to see the Shelly Interface here?

[tagyoureit]

Nope, that heater connection is to control a device through REM.

After you add the heater and Shelley interface (with correct connection info) and enable it, it should just work but you may need to restart the app.

[mojonba]

Working Good! Thanks and Happy Thanksgiving!